G2 THE NATURAL IITSTORT REVIEW. 



the plants of the several countries he cites as having analogous 

 climates, maj be accounted for by favouring climate alone. AVith 

 regard to the peopling of the northern districts by Coromandel 

 plants, few naturalists would, in the present state of geological 

 belief, deny that the immigration of these may have taken place 

 before the severance of Ceylon from the great Western Peninsula 

 of India ; and as the large Indian mammals of the island could only 

 thus have found their way across, it is reasonable to suppose that the 

 plants did so too. To account thus, however, for the generic and 

 almost specific identity of the mountain temperate Flora of Ceylon 

 with that of the Neilgherries, 400 miles distant, is not so easy, and, 

 except a great lowering of temperature be assumed, demands not 

 only continuous land, but a continuous mountain chain. In this 

 case the small size of many of the seeds of the plants, common to 

 both mountain-ranges, and other circumstances connected with their 

 facility of transport, (direct by currents, or indirect by birds, &c.) 

 must also be taken into account. 



Far more curious and suggestive, however, than the similarity of 

 the northern and mountain Floras of Ceylon, with those of Coro- 

 mandel and the Neilgherries, is the relation of the Southern Ceylon 

 Flora with the Malayan. This which alone would furnish materials 

 for a most interesting discussion is evidenced by the presence of gigan- 

 tic trees of DipterocarpecB^ of which Order Ceylon contains 8 genera 

 and 42 species, while in continental India there are probably not one- 

 sixth of that number; by the presence of Cycas BumpTiiii^ and by a 

 great many representative and identical species, scattered through 

 many Natural Orders. There is also a most curious relation established 

 between Madagascar and tropical Africa and Ceylon by means of a 

 species of Cacteae, Bhipsalis Cassytha, the only plant of its Order 

 found beyond the limits of America, by AngrcBcum and sundry other 

 plants; to which must be added, by way of negative evidence the 

 absence of Conifers and CupuliferaB in both countries. 



Our limits prevent us going further into detail as to the contents 

 of Mr. Thwaites' volume, which we the less regret, from believing it 

 to be only a precursor to a general Flora of the island, in which he 

 will doubtless expatiate upon these and kindred topics. 



"We should like too to have carried out our comparison between 

 Ceylon and the "West Indies, and show all the points in which they 



* Discovered by Mr. Thwaites wliilst the last part of his work was passinc 

 through the j)ress 



